Repetitive movements associated with autism are sometimes called stimming. The word stim is short for self-stimulation. It means repetitive movements that don’t appear to be purposeful, including hand flapping, rocking, blinking, pacing and repeating noises or words.
Among the criteria for an ASD diagnosis is “stereotyped or repetitive motor movements, use of objects or speech.” Some children engage in these repetitive movements to either block or increase sensory input, or as a means of alleviating distress. Children on the spectrum may stim both when they’re excited and when they’re frustrated or angry.
But these movements are only problematic if they interfere with a child’s functioning, including social interaction, daily activities and learning. Families worried about them are encouraged not to try to eradicate or draw undue attention to them, but instead to help children build communication skills and activities that may reduce time spent stimming.